Recently, laser systems that emit laser beams have been used in various fields. Particularly, a less-expensive laser system is equipped with a semiconductor laser. However, a semiconductor laser that emits green light has not yet been realized.
Patent Document 1 describes a laser system that emits green light by converting laser light emitted by a semiconductor laser to a secondary harmonic by a non-linear optical element.
Patent Document
    Patent Document 1: Japanese Laid-Open Patent Publication No. 6-132595